1. Technical Field
The present disclosure relates to a device for interconnecting bone anchors and, more particularly, to a transverse rod connector configured for multidirectional articulation with respect to the bone anchor.
2. Background of Related Art
Disease, the effects of aging, or physical trauma resulting in damage to the spine has been treated in many instances by fixation or stabilization of the effected vertebra. A wide variety of spinal fixation apparatuses have been employed in surgical procedures for correcting spinal injuries and the effects of spinal diseases. Many of these apparatuses commonly use a pair of longitudinal rods running in a relatively parallel relationship to each other and the spinal column. These rods are connected to coupling elements, which in turn are secured to the underlying vertebral bone by spinal bone fixation fasteners such as pedicle screws, hooks, and the like. The pair of longitudinal rods can be held in position relative to one another by transverse connectors, also known as transverse bridge elements or cross-connectors.
As the technology of spinal surgery has developed and improved, each of the spinal fixation components has also undergone improvements and modifications to address the shortcomings of conventional spinal fixation components. The natural anatomical variations in the spinal column of a subject are such that implanted spinal rods, while approximating a parallel relationship one to the other, can vary from that parallel relationship considerably and in multiple planes. For this reason, any transverse connector used to attach the two rods to each other should not be of a rigid design without the ability to be re-configured as needed during the process of implanting and attaching to the two opposing rods. While some improvements have been made in the articulation and re-configuration operation of transverse connectors during the implantation and rod connection process, a continuing need exists to provide an improved multidirectional articulating transverse connector that can adapt to a wide variance in the contours of the spinal column. Further, a need exists to provide such a transverse connector that can provide a secure attachment means to the spinal construct, most specifically in the posterior cervical spine region where a conventional cross connector cannot be inserted due to the short distance between bone anchor heads.
Conventional efforts to meet this need have fallen short of the desired transverse connector configuration. For example, U.S. Patent Publication No. 2006/0064091 to Ludwig includes first and second connector members for connection to the respective first and second bone anchors. The two connector members are connected one to the other by a fixed member, thereby not allowing adjustment between the connector members to accommodate the anatomy. In addition, the fixed member does not provide rotational freedom and needs to be bent into the appropriate configuration prior to attaching to the bone anchor.
For reasons discussed above, a continuing need exists for a transverse rod connector that provides ease of operation by the surgeon to simultaneously adjust in multiple dimensions one bone anchor connecting end of the system in relation to the other bone anchor connecting end of the system and to provide a device having secure attachment means to the bone anchor of the spinal construct.